“The policy problem facing the Department of Energy and Climate Change (DECC) in 2009 was immense. The Climate Change Act had just brought in the world’s first legally-binding greenhouse gas emissions reduction target. The UK had to cut 80 percent of emissions by 2050, taking 1990 levels as a baseline.”
Here is an interesting DECC blog on their 2050 Calculator Project which is open to the public, that seeks to examine (and model) the different ways the UK would transition to the mandated low carbon economy.
The 2050 Calculator Project is here.